<template>
  <div
    :class="[prefixCls]"
    v-clickoutside="onClickoutside"
    @mouseenter="handleMouseenter"
    @mouseleave="handleMouseleave">
    <div :class="[prefixCls + '-rel']" ref="reference" @click="handleClick">
      <slot></slot>
    </div>
    <transition name="transition-drop">
      <oolongSelectDropdown
        :class="dropdownCls"
        v-show="currentVisible"
        :placement="placement"
        ref="drop"
        @mouseenter.native="handleMouseenter"
        @mouseleave.native="handleMouseleave"
        :data-transfer="transfer"
        v-transfer-dom>
        <slot name="list"></slot>
      </oolongSelectDropdown>
    </transition>
  </div>
</template>
<script>

import oolongSelectDropdown from '../select/oolong-select-dropdown.vue';
import clickoutside from '../../directives/clickoutside';
import TransferDom from '../../directives/transfer-dom';
import {findComponentUpward, oneOf} from '../../utils/assist';

const prefixCls = 'oolong-dropdown';

export default {
  name: 'oolongDropdown',
  directives: {clickoutside, TransferDom},
  components: {oolongSelectDropdown},
  props: {
    trigger: {
      validator(value) {
        return oneOf(value, ['click', 'hover', 'custom']);
      },
      default: 'hover'
    },
    placement: {
      validator(value) {
        return oneOf(value, ['top', 'top-start', 'top-end', 'bottom', 'bottom-start', 'bottom-end', 'left', 'left-start', 'left-end', 'right', 'right-start', 'right-end']);
      },
      default: 'bottom'
    },
    visible: {
      type: Boolean,
      default: false
    },
    transfer: {
      type: Boolean,
      default: false
    }
  },
  computed: {
    transition() {
      return ['bottom-start', 'bottom', 'bottom-end'].indexOf(this.placement) > -1 ? 'slide-up' : 'fade';
    },
    dropdownCls() {
      return {
        [prefixCls + '-transfer']: this.transfer
      };
    }
  },
  data() {
    return {
      prefixCls: prefixCls,
      currentVisible: this.visible
    };
  },
  watch: {
    visible(val) {
      this.currentVisible = val;
    },
    currentVisible(val) {
      if (val) {
        this.$refs.drop.update();
      } else {
        this.$refs.drop.destroy();
      }
      this.$emit('on-visible-change', val);
    }
  },
  methods: {
    handleClick() {
      if (this.trigger === 'custom') return false;
      if (this.trigger !== 'click') {
        return false;
      }
      this.currentVisible = !this.currentVisible;
    },
    handleMouseenter() {
      if (this.trigger === 'custom') return false;
      if (this.trigger !== 'hover') {
        return false;
      }
      if (this.timeout) clearTimeout(this.timeout);
      this.timeout = setTimeout(() => {
        this.currentVisible = true;
      }, 250);
    },
    handleMouseleave() {
      if (this.trigger === 'custom') return false;
      if (this.trigger !== 'hover') {
        return false;
      }
      if (this.timeout) {
        clearTimeout(this.timeout);
        this.timeout = setTimeout(() => {
          this.currentVisible = false;
        }, 150);
      }
    },
    onClickoutside(e) {
      this.handleClose();
      if (this.currentVisible) this.$emit('on-clickoutside', e);
    },
    handleClose() {
      if (this.trigger === 'custom') return false;
      if (this.trigger !== 'click') {
        return false;
      }
      this.currentVisible = false;
    },
    hasParent() {
//                const $parent = this.$parent.$parent.$parent;
      const $parent = findComponentUpward(this, 'oolongDropdown');
      if ($parent) {
        return $parent;
      } else {
        return false;
      }
    }
  },
  mounted() {
    this.$on('on-click', (key) => {
      const $parent = this.hasParent();
      if ($parent) $parent.$emit('on-click', key);
    });
    this.$on('on-hover-click', () => {
      const $parent = this.hasParent();
      if ($parent) {
        this.$nextTick(() => {
          if (this.trigger === 'custom') return false;
          this.currentVisible = false;
        });
        $parent.$emit('on-hover-click');
      } else {
        this.$nextTick(() => {
          if (this.trigger === 'custom') return false;
          this.currentVisible = false;
        });
      }
    });
    this.$on('on-haschild-click', () => {
      this.$nextTick(() => {
        if (this.trigger === 'custom') return false;
        this.currentVisible = true;
      });
      const $parent = this.hasParent();
      if ($parent) $parent.$emit('on-haschild-click');
    });
  }
};
</script>
